diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index 2aedeac8a..6bd0534a6 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -33,6 +33,9 @@
Replace use of deprecated Class#newInstance() PR #49.
+
+ AbstractReferenceMap made easier for subclassing; PR #51.
+